added flush, expanded peek and background

1) Added "flush" function. This finds all matches on the board and removes them.
2) Expanded "peek" function so that it returns raw html in divs as well as client input, if relevant.
3) "Background" function now takes optional arguments that are passed to the function being called.
4) Messages are now logged in 1000-character increments rather than 70-character increments. This is done because messages were being logged on top of eachother, probably due to an underlying threadlock issue which I can't be bothered to figure out.